Cracked paint around expansion joints may seem like a small cosmetic issue, but it’s often a warning sign of deeper structural movement or improper surface preparation. Expansion joints are designed to absorb a building’s natural shifts caused by temperature changes and moisture fluctuations. When these joints fail or when coatings don’t stretch with the substrate, cracks appear — allowing water and air to penetrate the wall surface.
If left unaddressed, what starts as a fine split can quickly lead to water ingress, corrosion, and costly façade damage. Understanding why this happens and how to fix it can help you preserve both the integrity and appearance of your property.
Why Expansion Joint Cracking Happens
Every building expands and contracts as temperatures rise and fall. Expansion joints are installed to accommodate this movement and prevent structural stress. However, when the wrong type of paint or sealant is used, or if the surface hasn’t been properly prepared, the coating loses its flexibility.
Thermal Movement
During hot days, materials like concrete and steel expand; at night, they contract. Over time, this constant movement stretches rigid coatings beyond their capacity. As a result, cracks begin forming along joints and edges — the weakest points of the surface.
Moisture Intrusion
Moisture is another major culprit. When water enters through hairline gaps or unsealed joints, it gets trapped behind the paint film. As it expands and evaporates, it pushes the coating outward, causing blisters and cracks. In severe cases, trapped moisture can even lead to burst pipe repair situations if it affects plumbing behind façade walls.
Ageing Coatings
Older paints, particularly non-elastomeric types, lose their flexibility over time. They dry out, harden, and can no longer move with the building. This rigidity makes them more prone to cracking, especially at joints exposed to sunlight and rain.
The Hidden Risks of Ignoring Cracked Paint
When expansion joint cracks are neglected, water seeps through the smallest openings and reaches the substrate. This causes a chain reaction of issues that extend far beyond the surface appearance.
Water Penetration
Cracks act as direct pathways for water, which leads to damp patches, mould growth, and corrosion of embedded materials. Once moisture gets behind the coating, it weakens adhesion and accelerates peeling or flaking.
Structural Corrosion
Moisture infiltration can also corrode steel reinforcements or fixings within the wall. Over time, this corrosion expands, placing pressure on the render or concrete, leading to more visible damage and costly repairs.
Internal Damage
Water that travels inward through cracked joints can damage insulation, plaster, or electrical components. In multi-storey commercial buildings, this often results in widespread repair costs and operational downtime.
In short, what looks like a minor crack could signal a much bigger maintenance concern.
How Professional Remedial Work Restores the Façade
Simply repainting over cracked joints won’t solve the problem — it only hides it temporarily. The correct fix involves diagnosing the cause of movement, repairing the substrate, and applying flexible coatings that move with the building. This is where professional remedial builders Adelaide play a vital role.
Step 1: Assessment and Joint Inspection
Experienced remedial specialists begin by identifying the extent of cracking and the reasons behind it. They check for joint separation, damaged sealant, and underlying moisture. This inspection helps determine whether the issue is surface-level or structural.
Step 2: Joint Resealing and Repair
Once the cause is confirmed, joints are carefully cleaned and resealed using high-performance elastomeric materials. This ensures the new seal can expand and contract with thermal movement, maintaining waterproof integrity.
Step 3: Surface Preparation
All loose, flaking, or blistered paint is removed to create a clean, stable base. This step is crucial for adhesion and ensures that new coatings bond effectively without trapping moisture beneath.
Step 4: Recoating and Protection
After repairs, expert commercial building painting restores the façade’s finish and flexibility. Professionals use specialised paints designed for high-movement zones — products that stretch with the surface instead of cracking under pressure. These coatings also resist UV damage, moisture intrusion, and temperature extremes.
The combined expertise of remedial builders and commercial painters ensures your façade doesn’t just look good — it performs reliably under real-world conditions.
Why Coordination Between Trades Matters
One of the most common mistakes property owners make is calling in painters without consulting remedial specialists first. While a fresh coat can temporarily mask the problem, it won’t prevent it from returning.
Remedial builders address the structural and waterproofing side of the issue, while painters focus on protective coatings and appearance. Together, they create a complete, long-lasting solution. Without this coordination, even the best paint job can fail within months.
So, before repainting, always ensure the joints have been properly resealed and that the surface is sound. This approach saves time, reduces costs, and ensures durability.
Maintaining Your Coating for the Long Term
After restoration, maintenance becomes the key to keeping your building’s façade in top condition. Conduct routine inspections every 12 to 18 months, particularly after extreme weather or temperature shifts. Look for early signs like discolouration, micro-cracks, or minor peeling — these are your cues to act before larger issues develop.
Keeping gutters clean and checking drainage can also prevent water from pooling near joints. When drainage is blocked, water runoff can penetrate behind coatings, repeating the same cycle of damage.
If minor cracks appear again, schedule quick spot repairs rather than delaying until the damage spreads. Preventive care is far more affordable than large-scale restoration.
Conclusion: Fix the Cause, Not Just the Surface
Cracked paint along expansion joints is more than an aesthetic flaw — it’s a structural warning. Ignoring it risks moisture intrusion, corrosion, and internal damage. Fortunately, with the right approach, the problem is entirely fixable.
By engaging professional remedial builders for structural repairs and expert commercial building painting for flexible recoating, you ensure the job is done correctly from the inside out. Don’t just cover the cracks — address the underlying cause for a durable, weatherproof finish that lasts for years.
Schedule an inspection today to prevent further deterioration and safeguard your property’s façade against the next round of heat, rain, or movement.
